Triple valve for single-chamber compressed-air brakes



W. HILDEBR'AND.

TRIPLE VALVE FOR SiNGLE CHAMBER COMPRESSED AIR BRAKES. IAPPLICATHONFILED AUG.26, 1921.

l ,4;25,77, Patented Aug. 8, 1922,

Fig?

owrrao sra'rss DEL MAATGHAPPIJ H. ALBERT DE BABY A DUTCH COMPANY.

8500., OF AMSTERDAM, NETHERLANDS,

TRIPLE VALVE ronsmeLE-onAMBER coMrnEssEn-Am BRAKES.

To all whom it may concern:

Be it known that I, WVILHELM HILDEBRAND,

a German citizen, residing at Neue Bahnof the kind in which theauxiliary air reservoir is divided by a-dividing piston into twochambers the volume of which can be varied and which therefore permitsin addition to a graduated intensification of the action of the brake ofa graduated release thereof also and a constructional form of which isshown by way of example in Figure l of the specification of GermanPatent 291179. I

In the known triple valves for such brakes both the operation ofapplying or putting on the brake and also that of releasing or taking itoii iscontrolled by a common controlling device, which consists of twoslide valves, viz, a main and a graduator valve, which are placed oneabove the other and operated by a common controlling'piston.

In the knownquick-action and passenger train brake of the Kunze-Knorrconstructional type, the triple valve or" which is based on thisprinciple, the slide valves, owing to the considerable dimensions of thebrake cylinders, are rather large, with the result that there isproduced between them owing to the high working pressure or" about fiveatmospheres, a large amount of :triction, which in actual practice,leads frequently to inconveniences, inasmuch as owing to this frictionthe main valve is pre maturely carried along with the graduator valvewhen the brake is put on, that is to say before the graduator valve hascompleted the travel required by the play provided between the mainvalve"and the rear contact face of the frame-shaped piston rod of thecontrolling piston. This phenomenon is manifested in anundesirable'manner on the action of the brake which consequently andnaturally takes place in a manner different to that corresponding to theintention of the engine driver working the-brake.

According to this inventionythis' disadvantage is obviated by providingthe triple Specification of Letters Eatent. Patented Aug, 8, 1922,Application fi led August 26, 1921. Serial No. 495,513.-

valve with a-separate controlling device for both the operation ofputting on and taking off the-brake, the two controlling pistonswhichioperate these controlling devices being connected on one side withthe main train pipe and therefore always exposedon thisside to thepressure in the-main train pipe, while the slide 'valve chamber, inwhich the controlling device which regulates the 1 operation of puttingon the brake is 0on v tained, is connected to that chamber of theauxiliary air reservolr which furnishes coinpressed air to the slnglechamber brake cylinder when the brake is put on, while on the 1 contrarythe slide valve chamber for the controlling device which regulates the.operations of taking the brake off is connected to the other chamber ofthe auxiliary air. reservoir. This arrangement affords the additionaladvantage that two separate posia tions of the brake, a working and aquickaction position can be provided, without there being any fear of anunintentional jumping of the working brake position into the quickaotionbrake position, because the comparatively small contents of the chamberof the auxiliary air reservoir which supplies compressed air to thesingle chamber brake cylinder when the brake is put on, suffers a largeamount of expansion, so that its pressure, which decreases only slowlywhen the brake is normally applied, is by no means capable of overcomingthe pressure in the main train pipe. acting on the other side of thecontrolling piston.

As it is possible, owing to this distribution of the work to-two'different controlling devices, to make these, which according to thisinvention are constructed in the form of slide valves, of smallerdimensions than has been possible where main and graduator slide valvesare employed, the total frictional work which has to .be performed isalso less than in the type of construction which has hitherto beenusual.

A constructionalform of the invention is illustrated in the drawing byway of eX- ample as applied to" a single chamber brake, the auxiliaryair reservoir of which is divided into two variable chambers by adividing piston, which under certain circumstances acts as a brakeiston. I c

Figure 1 shows a trip e valve according to the controlling device out ofthe present invention in section, in conjunclan tl the eerre pcndmg br eaura rajtus, (hag ammat cally shown; in the f lling i ori'elease"position.

Figure 2 shows the device for controlling the taking off oif the brakein the position which it assumes each time the brake is pplied: M

Figure 8 shows the controlling device for regulating the operation ofputtingon the brake in the working brake position. Figure t shows thesame in the quickaction position. a I i 1 y The triple valve G isconnected. at L to the continuousrnain train pipe. It has the twopistonchambers I and II which are; in open connection with the. main trainpipe and in whichare contained the two controllingpistons k and 75 Thepistonk is con:

nected inthe well known way with a certain amountoft play to the slidevalve S which regulates the operation of putting the brake on. "Thepiston 70 on the contrary, is rigidl connected to the slide valve S?which serves to regulate the operation oftaking the brake off. J isthewell known single chains 1 berbrake cylinder with the pistonZ. H is theair reservoir, which is divided by the piston m into two chambers A andB. K is a chamber which isconnected to the auxiliary air reservoir andincreases the chamber Aifill/l is a receiving chamber which in therelease position. 1s connected to the main train pipe and acceleratesthe release of the rake after it has been applied. 12 is he.

gracluator valve provided in the well known way in. the main slidevalveyr 1s a non-return valve built into the pipe 3 leading to the brakecylinder J. V is a valve the purpose.

and action of which WVllIubG more fully describedwhereatter. a

The action of the apparatus is as follows:

. Supposing. the brake to be charged and the controlling devices in therelease position shown injFigure1,compressed air will be allowed toescape from the main train pipe L in the well known way through thedrivers brake valve for the purposeo'f initiating an application of thebrake. At every drop in the pressure in the main train pipe thecontrolling piston 70 assumes the position shown in Figure 2, in whichit shuts off all the: ports controlled by it. i It receives its movementfrom the pressurein the auxiliary reservoir which acts on its right handside, the chamber IV is connected by the pipe 5 to the chamber and thechamber A of the auxiliary air reservoir H. The controlling piston 7::Whiclrregulates the admission at the compressed air to the singlechamber brake cylinder when the brakeis applied, has assumed on aso-called working application otthe brake the position shown in Figure 3in consequence of the fall of pressure in the main train pipe." Atthepressure in themain train eeann? same timethe graduator valve providedin the controll n slide va ve S ha first the chamber G of the singlechamber brake cylinder J. where it acts in thewell known way. If at thesame time the reduction of pipe has only been a slight one, thecompressed air flowing from. B to C by the route described suffers agreater reduction of: pressure than, the pressure inwthe main tra n pipedoes with the result thatthe controllingpiston isinoves so far towardsthe right that it closes the graduator valve p thus bringing aboutthecut oil position of the brake. y I

. When the brake has been applied and it is found that the action of thebrake is too powerful, a graduated reduction otthe action of the brakeis brought about by slightly increasing the pressure in the main trainpipe by means of the drivers brake valve. When thisis done both thecontrollingpistons in the triple valve casing as sume the releaseposition shown in Figure 1.

The compressed air then escapes through thepipe 3 and the pipe 4t whichbranches off therefrom by theright hand. hollow in the slide valves? andthe opening 9 leading into the open air from the chamber C of thesinglechamber brake cylinder until this connection is cut off, whichtakes place as soon as the air flowing out of the main train pipethrough the pipe Z, the left hand hollow in the valve SF and the pipe 2into the B chamber of the auxiliary air reservoir II has pushed thepiston m therein over to the right and consequently has produced an increased-pressure in the A chamber of; the

auxiliary air reservoira-nd the chamber IV connected with it owing tothe presence of the small counter piston n The piston 7c is then pushedover towards the left and the operation of releasing the brakeinterrupted before it is completed. Owing to the pres ence of thechamber M the increase of the pressure in the 'chamberB of the auxiliaryreservoir is effected comparatively quickly. this means it is possibleto bring about any desired greateror smaller grades of the releaseof thebrake,

If a quick- .or emergency action of the brake is initiated. and. themain train pipe rapidlyand abundantly emptied by the drivers brake valvefor this purpose, then both the controlling pistons rapidly assume theirleft hand position, and the slide valve S at the same time again cutsoil all the ports which it controls and the slide valve S establishesconnection between the pipes 6 and 3 (see Figure 4). Air therefore flowsfrom the main pipe into the C chamber of the single-chamber brakecylinder. At the same time the pipe 7 leading through the valve V to thebrake cylinder is uncovered by the controlling slide valve S and thecompressed air from the chamber B of the auxiliary air reservoirtherefore flows through the pipe and the chamber 111 into the pipe 7,forces the valve V downwards against the action of the spring pressingon it from below thereby closing the holes in the body of the valvewhich register with one or more openings leading into the open air, andpasses through the openings 12 (which are now uncovered) and the pipe 3into the chamber C of the single chamber brake cylinder. If anequalization of pressure has taken placebetween the brake cylinder andthe chamber B of the auxiliary air reservoir, the spring providedbeneath the valve V closes it and the compressed air still contained inB escapes through the openings 11 into the atmosphere. The piston m ofthe auxiliary reservoir which has already moved over towards the leftunder the action of the excess of pressure acting in the chamber A andin the chamber K is pushed into its extreme left hand position. The loop0 is brought into contact with a bolt in the brake rigging and theaction of the brake is intensified by the co-operation of the piston mto the highest possible degree.

Q If after the brake has been applied the pressure in the main trainpipe is again raised by the drivers brake valve for the purpose oftaking the brake ofi', the controlling devices again assume the poslt onshown in Figure 1. When they do so shde valve S which controls theapplication of the brake closes all the ports which it controls, afterthe graduator valve 29 has first been closed. The slide valve S whicheflects the operation of releasing the brake returns to its right handextreme position, connecting the main train pipe L to the chamber B ofthe auxiliary air reservoir H by means of the port Z, the left handhollow in theslide valve and the pipe 2. As soon as the piston in thislatter has assumedits right hand extreme position under the action ofthe increasing pressure in B, air

flows from the main train pipe throughthe small opening 9 into the Achamber, fills the chamber K and passes through the pipe 5 i into thechamber IV of the triple valve caswhile on the other side the pistonwhich" moves the controlling slide valve S is subj ected to the pressurein the chamber B and the one which regulates the operation of releasingthe brake is subjected to the pressure in the chamber A of the auxiliaryair reservoir.

hat I claim and desire to secure by Letters Patent of the United Statesis I 1. In a triple valve for a single chamber compressed air brake, aslide valve for controlling the operation of applying the brake and asecond slide valve tor'controlling the operation of releasing the brakeand two pistons for operating respectively the said slide valves, meanswhereby one side of each of said pistons is subjected to the pressure inthe main train pipe the other side of one piston to one chamber of theauxiliary air reservoir and the other side of the second piston to theother chamber of the said auxiliary air reservoir, substantially as andfor the purpose specified.

2. Triplevalve for single-chamber compressed air brakes with anauxiliary air reservoir divided into two chambers by a movable dividingpiston, characterized by the fact that the control of the operations ofapplying and releasing the brake are each effected by a separatecontrolling slide valve, each of which is operated by a controllingpiston subjected on one side to the pressure in the main train pipe andof which the one which regulates the operation of applying the brake issubjected on its other side to the pressure in that chamber of theauxiliary air reservoir which, when the brake is applied, delivers itspressure into the single-chamber brake cylinder, whlle the controllingpiston which regulates the operation of releasing the brake is subjectedon 1ts other side to the pressure in the other chamber of the auxiliaryair reservoir.

WVILHELM HILDEBRAND.

